Proton Therapy for Anal Cancer

James M. Metz, MD, Editor-in-Chief of OncoLink and Assistant Professor of Radiation Oncology at the Hospital of the University of Pennsylvania, responds:

Proton beam therapy is being explored as a possible form of treatment for a number of cancers. To date, no clinical studies have been done specifically treating anal cancer. However, there is interest in expanding the use of protons to treat a number of gastrointestinal malignancies. Because many of these cancers are currently treated with combined chemotherapy and radiation therapy, which has a higher complication rate then either therapy alone, proton-based radiation may offer benefits due to the superior dose deposition within the target and reduced dose to normal organs – resulting in potentially fewer and less severe side effects. I am not aware of any clinical trials that have been started specifically for anal cancer. As the availability of proton therapy expands, this will certainly become an area of clinical investigation.